[URL="http://api.tweetmeme.com/share?url=http://espn.go.com/nfl/story/_/id/7182370/nfl-instructs-refs-alert-concussion-signs&service=bit.ly&source=espn"][IMG]http://api.tweetmeme.com/imagebutton.gif?url=http://espn.go.com/nfl/story/_/id/7182370/nfl-instructs-refs-alert-concussion-signs[/IMG][/URL]The NFL will instruct game officials to be more alert to concussion symptoms this week in the wake of the head trauma and subsequent seizure suffered by San Diego Chargers guard Kris Dielman on Oct. 23.